Ok...my friend is putting a 4.10 gear in his Camaro...and said he'd give me the 3.42 that came out of his car if i could use it...so theres my question

Will a set of gears from a 4th gen (94 to be exact) fit my 3rd gen rearend?

yes, more or less depending on your carrier series and assuming you also have a 10 bolt rear

thanks man!